CN106795107B

CN106795107B - Sulfonate compound, photoacid generator, and resin composition for lithography

Info

Publication number: CN106795107B
Application number: CN201580054732.1A
Authority: CN
Inventors: 冈昌明; 中村友治
Original assignee: San Apro KK
Current assignee: San Apro KK
Priority date: 2014-11-07
Filing date: 2015-10-13
Publication date: 2021-05-28
Anticipated expiration: 2035-10-13
Also published as: TWI698419B; EP3216783A4; KR102354196B1; TW201617312A; CN106795107A; US10450266B2; EP3216783B1; US20170233336A1; JP6622210B2; KR20170080574A; EP3216783A1; WO2016072049A1; JPWO2016072049A1

Abstract

The present invention provides a non-ionic photoacid generator containing a sulfonate compound having high photosensitivity to i-rays, excellent heat resistance stability, and excellent solubility in a hydrophobic material, and a resin composition for lithography containing the non-ionic photoacid generator, the present invention is a sulfonate compound characterized by being represented by general formula (1). [ in the formula (1), R1 represents an aryl group having 6 to 18 carbon atoms or a heterocyclic hydrocarbon group having 4 to 20 carbon atoms. R2 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms. R3 represents a hydrocarbon group having 1 to 18 carbon atoms (some or all of the hydrogens may be replaced with fluorine)]

Description

Sulfonate compound, photoacid generator, and resin composition for lithography

Technical Field

The present invention relates to a sulfonic acid ester compound, a photoacid generator, and a resin composition for lithography. More particularly, the present invention relates to a nonionic photoacid generator suitable for generating a strong acid by the action of ultraviolet (i-ray) rays, and a resin composition for lithography containing the photoacid generator.

Background

Conventionally, in the field of microfabrication represented by the production of semiconductors, a photolithography process using i-rays having a wavelength of 365nm as exposure light has been widely used.

As a resist material used in the photolithography step, for example, a resin composition containing a polymer having a tert-butyl ester group of a carboxylic acid or a tert-butyl carbonate group of phenol and a photoacid generator is used. As the photoacid generator, an ionic photoacid generator such as a triarylsulfonium salt (patent document 1), a phenacylsulfonium salt having a naphthalene skeleton (patent document 2), an acid generator having an oxime sulfonate structure (patent document 3), and a nonionic acid generator such as an acid generator having a sulfonyldiazomethane structure (patent document 4) are known. By irradiating the resist material with ultraviolet rays, the photoacid generator is decomposed to generate a strong acid. Further, by heating (PEB) after exposure, the tert-butyl ester group or tert-butyl carbonate group in the polymer is dissociated by the strong acid to form a carboxylic acid or a phenolic hydroxyl group, and the ultraviolet-irradiated portion becomes easily soluble in an alkaline developer. This phenomenon is utilized for pattern formation.

However, as the photolithography process becomes finer, the influence of swelling, which causes swelling of the pattern in the unexposed area by the alkaline developer, becomes large, and it is necessary to suppress swelling of the resist material.

In order to solve these problems, the following methods are proposed: the polymer in the resist material contains an alicyclic skeleton, a fluorine-containing skeleton, or the like to form hydrophobicity, thereby suppressing swelling of the resist material.

However, the ionic photoacid generator has insufficient compatibility with a hydrophobic material containing an alicyclic skeleton, a fluorine-containing skeleton, and the like, and therefore has the following problems: since phase separation occurs in the resist material, sufficient resist performance cannot be exhibited, and patterning cannot be performed. On the other hand, although the nonionic photoacid generator has good compatibility with hydrophobic materials, it has a problem of insufficient sensitivity to i-rays; and a narrow margin (allowance) because of insufficient heat resistance stability and thus decomposition in post-exposure heating (PEB).

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 50-151997

Patent document 2: japanese laid-open patent publication No. 9-118663

Patent document 3: japanese laid-open patent publication No. H06-77433

Patent document 4: japanese laid-open patent publication No. 10-213889

Disclosure of Invention

Accordingly, an object is to provide a nonionic photoacid generator which has high photosensitivity to i-rays, is excellent in heat resistance stability, and is excellent in solubility in a hydrophobic material.

The present inventors have made studies to achieve the above object, and as a result, have completed the present invention.

That is, the present invention is a sulfonic acid ester compound represented by the general formula (1).

[ in the formula (1), R1 represents an aryl group having 6 to 18 carbon atoms or a heterocyclic hydrocarbon group having 4 to 20 carbon atoms. R2 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms. R3 represents a hydrocarbon group having 1 to 18 carbon atoms (some or all of the hydrogens may be substituted with fluorine) ]

The sulfonate compound of the present invention and the nonionic photoacid generator (a) containing the sulfonate compound are nonionic and have excellent compatibility with a hydrophobic material as compared with an ionic photoacid generator. Further, since the nonionic photoacid generator has an imide skeleton as a site that absorbs i-rays, the nonionic photoacid generator is easily decomposed by irradiation with i-rays, and sulfonic acid as a strong acid is generated. Further, the nonionic photoacid generator (a) has an imide skeleton, and therefore, is excellent in heat resistance stability.

Therefore, the resin composition (Q) for lithography containing the nonionic photoacid generator (a) of the present invention has high sensitivity to i-rays, and has excellent workability because the margin in post-exposure heating (PEB) is wide.

Detailed Description

The sulfonic acid compound of the present invention is represented by the above general formula (1).

In the formula (1), R1 is an aryl group having 6-18 carbon atoms or a heterocyclic alkyl group having 4-20 carbon atoms.

Examples of the aryl group having 6 to 18 carbon atoms in R1 include phenyl, naphthyl, anthryl, biphenyl, phenanthryl, pyrenyl and the like.

Examples of the heterocyclic hydrocarbon group having 4 to 20 carbon atoms represented by R1 include furyl, thienyl, pyranyl, pyridyl, thiazolyl, coumarinyl, carbazolyl, thioxanthyl and the like.

The aryl group having 6 to 18 carbon atoms and the heterocyclic hydrocarbon group having 4 to 20 carbon atoms of R1 may have a substituent (T). Examples of the substituent (T) include an alkyl group, a hydroxyl group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, and a halogen atom. The number of the substituent (T) may be one or two or more.

Examples of the alkyl group include a straight-chain alkyl group having 1 to 18 carbon atoms (e.g., methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, and n-octadecyl groups), a branched-chain alkyl group having 1 to 18 carbon atoms (e.g., isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, and isooctadecyl groups), a cycloalkyl group having 3 to 18 carbon atoms (e.g., cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and 4-decylcyclohexyl groups), and a straight-chain or branched-chain fluoroalkyl group having 1 to 3 carbon atoms (e.g., trifluoromethyl, pentafluoroethyl, and heptafluorobutyl groups).

Examples of the alkoxy group include a linear or branched alkoxy group having 1 to 18 carbon atoms (e.g., methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, hexyloxy, decyloxy, dodecyloxy, octadecyloxy, etc.), and the like.

Examples of the alkylcarbonyl group include a linear or branched alkylcarbonyl group having 2 to 18 carbon atoms (including carbonyl carbons) (e.g., acetyl group, propionyl group, butyryl group, 2-methylpropionyl group, heptanoyl group, 2-methylbutyryl group, 3-methylbutyryl group, octanoyl group, decanoyl group, dodecanoyl group, and octadecanoyl group).

Examples of the arylcarbonyl group include arylcarbonyl groups having 7 to 11 carbon atoms (including carbonyl carbons) (e.g., benzoyl and naphthoyl groups).

Examples of the alkoxycarbonyl group include a linear or branched alkoxycarbonyl group having 2 to 19 carbon atoms (including the carbonyl carbon) (e.g., a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, a butoxycarbonyl group, an isobutoxycarbonyl group, a sec-butoxycarbonyl group, a tert-butoxycarbonyl group, an octoxycarbonyl group, a tetradecyloxycarbonyl group, and an octadecyloxycarbonyl group).

Examples of the aryloxycarbonyl group include aryloxycarbonyl groups having 7 to 11 carbon atoms (including a carbonyl carbon group) (e.g., a phenoxycarbonyl group and a naphthyloxycarbonyl group).

Examples of the arylthiocarbonyl group include arylthiocarbonyl groups having 7 to 11 carbon atoms (including carbonyl carbons) (e.g., phenylthiocarbonyl group and naphthyloxycarbonyl group).

Examples of the acyloxy group include a linear or branched acyloxy group having 2 to 19 carbon atoms (e.g., an acetoxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, an isobutylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, an octylcarbonyloxy group, a tetradecylcarbonyloxy group, and an octadecylcarbonyloxy group).

Examples of the arylthio group include arylthio groups having 6 to 20 carbon atoms (phenylthio group, 2-methylphenylthio group, 3-methylphenylthio group, 4-methylphenylthio group, 2-chlorophenylthio group, 3-chlorophenylthio group, 4-chlorophenylthio group, 2-bromophenylthio group, 3-bromophenylthio group, 4-bromophenylthio group, 2-fluorophenylthio group, 3-fluorophenylthio group, 4-fluorophenylthio group, 2-hydroxyphenylthio group, 4-hydroxyphenylthio group, 2-methoxyphenylthio group, 4-methoxyphenylthio group, 1-naphthylthio group, 2-naphthylthio group, 4- [ 4- (phenylthio) benzoyl ] phenylthio group, 4- [ 4- (phenylthio) phenoxy ] phenylthio group, 4- [ 4- (phenylthio) phenyl ] phenylthio group, 4- (phenylthio) phenylthio group, 4-benzoylphenylthio group, 4-benzoyl-2-chlorophenylthio group, 4-benzoyl-3-chlorophenylthio group, 3-fluorophenylthio, 4-benzoyl-3-methylthiophenylthio, 4-benzoyl-2-methylthiophenylthio, 4- (4-methylthiobenzoyl) phenylthio, 4- (2-methylthiobenzoyl) phenylthio, 4- (p-methylbenzoyl) phenylthio, 4- (p-ethylbenzoyl) phenylthio, 4- (p-isopropylbenzoyl) phenylthio, 4- (p-tert-butylbenzoyl) phenylthio, etc.), etc.

Examples of the alkylthio group include a straight-chain or branched alkylthio group having 1 to 18 carbon atoms (e.g., a methylthio group, an ethylthio group, a propylthio group, an isopropylthio group, a butylthio group, an isobutylthio group, a sec-butylthio group, a tert-butylthio group, a pentylthio group, an isopentylthio group, a neopentylthio group, a tert-pentylthio group, an octylthio group, a decylthio group, a dodecylthio group, and an isooctadecylthio group).

Examples of the aryl group include aryl groups having 6 to 10 carbon atoms (e.g., phenyl, tolyl, dimethylphenyl, naphthyl, etc.).

Examples of the heterocyclic hydrocarbon group include a heterocyclic hydrocarbon group having 4 to 20 carbon atoms (thienyl, furyl, pyranyl, pyrrolyl, thienyl, pyrrolyl, pyridyl,

azolyl, thiazolyl, pyridyl, pyrimidinyl, pyrazinyl, indolyl, benzofuranyl, benzothienyl, quinolinyl, isoquinolinyl, quinolinyl

Quinolinyl, quinazolinyl, carbazolyl, acridinyl, phenothiazinyl, phenazinyl, xanthenyl, thienyl, phenonyl

Oxazine and thiophene

Thienyl, chromanyl (chromanyl), isochromanyl (isochromanyl), dibenzothienyl, xanthonePhenyl, thioxanthyl, dibenzofuranyl, and the like).

Examples of the aryloxy group include aryloxy groups having 6 to 10 carbon atoms (e.g., phenoxy and naphthoxy groups).

Examples of the alkylsulfinyl group include a linear or branched alkylsulfinyl group having 1 to 18 carbon atoms (e.g., methylsulfinyl, ethylsulfinyl, propylsulfinyl, isopropylsulfinyl, butylsulfinyl, isobutylsulfinyl, sec-butylsulfinyl, tert-butylsulfinyl, pentylsulfinyl, isopentylsulfinyl, neopentylsulfinyl, tert-pentylsulfinyl, octylsulfinyl, and isooctadecylsulfinyl).

Examples of the arylsulfinyl group include arylsulfinyl groups having 6 to 10 carbon atoms (e.g., phenylsulfinyl, tolylsulfinyl, and naphthylsulfinyl).

Examples of the alkylsulfonyl group include linear or branched sulfonyl groups having 1 to 18 carbon atoms (e.g., methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, isopropylsulfonyl group, butylsulfonyl group, isobutylsulfonyl group, sec-butylsulfonyl group, tert-butylsulfonyl group, pentylsulfonyl group, isopentylsulfonyl group, neopentylsulfonyl group, tert-pentylsulfonyl group, octylsulfonyl group, and octadecylsulfonyl group).

Examples of the arylsulfonyl group include arylsulfonyl groups having 6 to 10 carbon atoms { phenylsulfonyl group, tolylsulfonyl group (tosyl group), naphthylsulfonyl group, and the like }.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.

Among these substituents (T), from the viewpoints of ease of synthesis, absorption wavelength region, and heat-resistant stability, a hydroxyl group, an alkyl group, an alkoxy group, an arylcarbonyl group, an aryloxycarbonyl group, an arylthio group, an aryl group, an aryloxy group, an arylsulfinyl group, an arylsulfonyl group, a fluorine atom, and a chlorine atom are preferable, and a hydroxyl group, an alkoxy group, an arylthio group, a fluorine atom, and a chlorine atom are particularly preferable.

In R1, preferred are phenyl, naphthyl, anthracenyl, biphenyl, phenanthryl, pyrenyl, furyl, thienyl, pyranyl, pyridyl, thiazolyl, coumarinyl, carbazolyl and thioxanthone groups, and more preferred are phenyl, naphthyl, anthracenyl, coumarinyl and thioxanthone groups.

In the formula (1), R2 is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, or an aryl group having 6 to 18 carbon atoms.

Examples of the C1-18 alkyl group represented by R2 include C1-18 straight-chain alkyl groups (such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, and n-octadecyl groups), C1-18 branched-chain alkyl groups (such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, and isooctadecyl groups), C3-18 cycloalkyl groups (such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and 4-decylcyclohexyl groups), and C1-3 straight-chain or branched-chain fluoroalkyl groups (such as trifluoromethyl, pentafluoroethyl, and heptafluorobutyl groups).

Examples of the alkenyl group having 2 to 18 carbon atoms represented by R2 include a straight-chain or branched alkenyl group such as a vinyl group, an allyl group, a 1-propenyl group, an isopropenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-methyl-1-propenyl group, a 1-methyl-2-propenyl group, a 2-methyl-1-propenyl group, a 2-methyl-2-propenyl group, a 1-pentenyl group, a 2-pentenyl group, a 3-pentenyl group, a 4-pentenyl group, a 1-methyl-1-butenyl group, a 2-methyl-2-butenyl group, a 3-methyl-2-butenyl group, a 1, 2-dimethyl-1-propenyl group, a 1-decenyl group, a 2-decenyl group, an 8-decenyl group, a 1-dodecenyl group, a 2-dodecenyl group, and a.

Examples of the alkynyl group having 2 to 18 carbon atoms in R2 include straight-chain or branched-chain alkynyl groups such as an ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-methyl-2-propynyl group, 1-pentynyl group, 2-pentynyl group, 3-pentynyl group, 4-pentynyl group, 1-methyl-2-butynyl group, 1, 2-dimethyl-2-propynyl group, 1-decynyl group, 2-decynyl group, 8-decynyl group, 1-dodecylynyl group, 2-dodecylynyl group, and 10-dodecylynyl group.

Examples of the aryl group having 6 to 18 carbon atoms represented by R2 include a phenyl group, a tolyl group, a dimethylphenyl group, a naphthyl group, an anthracenyl group, a biphenyl group, a pentafluorophenyl group, and the like.

In R2, a hydrogen atom or an alkyl group having 1 to 18 carbon atoms is preferable, and a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group or a tert-butyl group is particularly preferable.

R3, which is an essential functional group for partially decomposing a sulfonate by ultraviolet irradiation, is a hydrocarbon group having 1 to 18 carbon atoms (some or all of the hydrogens may be substituted with fluorine) which may have a substituent. As the substituent, the groups exemplified as the substituent (T) can be used. Examples of the hydrocarbon group having 1 to 18 carbon atoms include alkyl groups, aryl groups, and heterocyclic hydrocarbon groups.

Examples of the alkyl group include a straight-chain alkyl group having 1 to 18 carbon atoms (e.g., methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, and n-octadecyl groups), a branched-chain alkyl group having 1 to 18 carbon atoms (e.g., isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, and isooctadecyl groups), and a cycloalkyl group having 3 to 18 carbon atoms (e.g., cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 4-decylcyclohexyl, and 10-camphoryl groups).

Examples of the aryl group include aryl groups having 6 to 10 carbon atoms (e.g., phenyl group, tolyl group, dimethylphenyl group, naphthyl group, and pentafluorophenyl group).

Azolyl, quinazolinyl, carbazolylAcridinyl, phenothiazinyl, phenazinyl, xanthenyl, thienyl, phenodiazinyl

Oxazine and thiophene

Thiayl, chromanyl, isochromanyl, dibenzothienyl, xanthonyl, thioxanthonyl, dibenzofuranyl, and the like).

Examples of the group in which some or all of the hydrogens of the hydrocarbon group having 1 to 18 carbon atoms which may have a substituent are substituted with fluorine include a straight-chain alkyl group (RF1), a branched-chain alkyl group (RF2), a cycloalkyl group (RF3) and an aryl group (RF4) in which the hydrogen atom represented by CxFy is substituted with a fluorine atom.

Examples of the straight-chain alkyl group (RF1) in which a hydrogen atom is substituted with a fluorine atom include trifluoromethyl (x ═ 1, y ═ 3), pentafluoroethyl (x ═ 2, y ═ 5), nonafluorobutyl (x ═ 4, y ═ 9), perfluorohexyl (x ═ 6, y ═ 13), and perfluorooctyl (x ═ 8, y ═ 17).

Examples of the branched alkyl group (RF2) in which a hydrogen atom is substituted with a fluorine atom include perfluoroisopropyl (x ═ 3, y ═ 7), perfluoro-tert-butyl (x ═ 4, y ═ 9), and perfluoro-2-ethylhexyl (x ═ 8, y ═ 17).

Examples of the cycloalkyl group (RF3) in which a hydrogen atom is substituted with a fluorine atom include perfluorocyclobutyl (x ═ 4, y ═ 7), perfluorocyclopentyl (x ═ 5, y ═ 9), perfluorocyclohexyl (x ═ 6, y ═ 11), and perfluoro (1-cyclohexyl) methyl (x ═ 7, y ═ 13).

Examples of the aryl group (RF4) in which a hydrogen atom is substituted with a fluorine atom include a pentafluorophenyl group (x ═ 6, y ═ 5) and a 3-trifluoromethyltetrafluorophenyl group (x ═ 7, y ═ 7).

In R3, a C1-18 linear alkyl group, a C1-18 branched alkyl group, a C3-18 cycloalkyl group, a C6-10 aryl group or a C4-20 heterocyclic hydrocarbon group is preferable, and a methyl group, an ethyl group, a n-propyl group, a n-butyl group, a n-pentyl group, a n-octyl group, a n-decyl group, a n-dodecyl group, an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, an isohexyl group, an isooctadecyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a 4-decylcyclohexyl group and a 10-camphor.

Preferred specific examples of the sulfonate compound represented by the general formula (1) include the following compounds from the viewpoints of ease of synthesis, adjustment of an absorption wavelength range, and heat resistance stability. In the structural formula of the compound, N-, O-, -represents N-CH₃、O－CH₃、－CH₃. The same applies to the following.

The method for synthesizing the sulfonate compound of the present invention is not particularly limited as long as it can synthesize the desired product, and may be, for example, a method of synthesizing a sulfonate compound by N-hydroxyacyl as a precursorImine compound (P1) and (R3-SO)₂)₂Reaction of sulfonic anhydride represented by O or salt of N-hydroxyimide compound (P1) with R3-SO₂Sulfonyl chloride as shown by Cl.

The nonionic photoacid generator (a) of the present invention may be dissolved in a solvent that does not inhibit the reaction in advance, so as to be easily dissolved in the resist material.

Examples of the solvent include carbonates (propylene carbonate, ethylene carbonate, 1, 2-butylene carbonate, dimethyl carbonate, diethyl carbonate, and the like); esters (ethyl acetate, ethyl lactate, beta-propiolactone, beta-butyrolactone, gamma-butyrolactone, delta-valerolactone, epsilon-caprolactone, and the like); ethers (ethylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol dimethyl ether, triethylene glycol diethyl ether, tripropylene glycol dibutyl ether, etc.); and ether esters (ethylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and the like).

When a solvent is used, the solvent is preferably used in an amount of 15 to 1000 parts by weight, more preferably 30 to 500 parts by weight, based on 100 parts by weight of the photoacid generator of the present invention.

Since the resin composition (Q) for lithography of the present invention contains the nonionic photoacid generator (a) as an essential component, the solubility of the exposed portion and the unexposed portion in the developer is different by ultraviolet irradiation and post-exposure heating (PEB). The nonionic photoacid generator (a) may be used singly or in combination of two or more.

Examples of the resin composition (Q) for lithography include a mixture of a negative type chemically amplified resin (QN) and a nonionic photoacid generator (a); and a mixture of a positive type chemically amplified resin (QP) and a nonionic photoacid generator (A).

The negative chemical amplification resin (QN) is composed of a phenolic hydroxyl group-containing resin (QN1) and a crosslinking agent (QN 2).

The phenolic hydroxyl group-containing resin (QN1) is not particularly limited as long as it is a phenolic hydroxyl group-containing resin, and examples thereof include a novolak resin, polyhydroxystyrene, a copolymer of hydroxystyrene and styrene, hydroxystyrene, a copolymer of styrene and a (meth) acrylic acid derivative, a phenol-xylene glycol condensation resin, a cresol-xylene glycol condensation resin, a polyimide containing a phenolic hydroxyl group, a polyamic acid containing a phenolic hydroxyl group, and a phenol-dicyclopentadiene condensation resin. Among these phenolic hydroxyl group-containing resins, preferred are novolak resins, polyhydroxystyrene, copolymers of hydroxystyrene and styrene, hydroxystyrene, copolymers of styrene and (meth) acrylic acid derivatives, and phenol-xylylene glycol condensation resins. These phenolic hydroxyl group-containing resins (QN1) may be used singly or in combination of two or more.

The novolac resin can be obtained, for example, by condensing phenols and aldehydes in the presence of a catalyst.

Examples of the phenols include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p-butylphenol, 2, 3-xylenol, 2, 4-xylenol, 2, 5-xylenol, 2, 6-xylenol, 3, 4-xylenol, 3, 5-xylenol, 2,3, 5-trimethylphenol, 3,4, 5-trimethylphenol, catechol, resorcinol, pyrogallol, α -naphthol, and β -naphthol.

Examples of the aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, and benzaldehyde.

Specific examples of the novolak resin include a phenol/formaldehyde condensation novolak resin, a cresol/formaldehyde condensation novolak resin, a phenol-naphthol/formaldehyde condensation novolak resin, and the like.

The phenolic hydroxyl group-containing resin (QN1) may contain a phenolic low-molecular compound as a part of the component.

Examples of the phenolic low-molecular-weight compound include 4,4 '-dihydroxydiphenylmethane, 4' -dihydroxydiphenyl ether, tris (4-hydroxyphenyl) methane, 1-bis (4-hydroxyphenyl) -1-phenylethane, tris (4-hydroxyphenyl) ethane, 1, 3-bis [ 1- (4-hydroxyphenyl) -1-methylethyl ] benzene, 1, 4-bis [ 1- (4-hydroxyphenyl) -1-methylethyl ] benzene, 4, 6-bis [ 1- (4-hydroxyphenyl) -1-methylethyl ] -1, 3-dihydroxybenzene, 1-bis (4-hydroxyphenyl) -1- [ 4- [ 1- (4-hydroxyphenyl) -1-methylethyl ] phenyl ] ethane, 1,2, 2-tetrakis (4-hydroxyphenyl) ethane, 4' - { 1- [ 4- [ 1- (4-hydroxyphenyl) -1-methylethyl ] phenyl ] ethylidene } bisphenol, and the like. These phenolic low-molecular weight compounds may be used alone or in combination of two or more.

The content of the phenolic low-molecular compound in the phenolic hydroxyl group-containing resin (QN1) is preferably 40% by weight or less, and more preferably 1 to 30% by weight, based on 100% by weight of the phenolic hydroxyl group-containing resin (QN 1).

The weight average molecular weight of the phenolic hydroxyl group-containing resin (QN1) is preferably 2000 or more, and more preferably about 2000 to 20000, from the viewpoint of resolution, thermal shock property, heat resistance, residual film ratio, and the like of the insulating film obtained.

The content of the phenolic hydroxyl group-containing resin (QN1) in the negative-type chemically amplified resin (QN) is preferably 30 to 90 wt%, more preferably 40 to 80 wt%, based on 100 wt% of the entire composition from which the solvent is removed. When the content of the phenolic hydroxyl group-containing resin (QN1) is 30 to 90 wt%, a film formed using the photosensitive insulating resin composition has sufficient developability with an alkaline aqueous solution, and thus is preferable.

The crosslinking agent (QN2) is not particularly limited as long as it is a compound capable of crosslinking the phenolic hydroxyl group-containing resin (QN1) with a strong acid generated from the nonionic photoacid generator (a).

Examples of the crosslinking agent (QN2) include bisphenol A epoxy compounds, bisphenol F epoxy compounds, bisphenol S epoxy compounds, novolac epoxy compounds, resol epoxy compounds, poly (hydroxystyrene) epoxy compounds, oxetane compounds, methylol-containing melamine compounds, methylol-containing benzoguanamine compounds, methylol-containing urea compounds, methylol-containing phenol compounds, alkoxyalkyl-containing melamine compounds, alkoxyalkyl-containing benzoguanamine compounds, alkoxyalkyl-containing urea compounds, alkoxyalkyl-containing phenol compounds, carboxymethyl-containing melamine resins, carboxymethyl-containing benzoguanamine resins, carboxymethyl-containing urea resins, carboxymethyl-containing phenol resins, carboxymethyl-containing melamine compounds, carboxymethyl-containing benzoguanamine compounds, bisphenol F epoxy compounds, bisphenol S epoxy compounds, novolac S-containing epoxy compounds, novolac S-O-R compounds, novolac S-O-R compounds, poly (hydroxystyrene) S-R compounds, oxetane compounds, methylol-containing melamine compounds, A carboxymethyl group-containing urea compound, a carboxymethyl group-containing phenol compound, and the like.

Among these crosslinking agents (QN2), preferred are a methylol group-containing phenol compound, a methoxymethyl group-containing melamine compound, a methoxymethyl group-containing phenol compound, a methoxymethyl group-containing glycoluril compound, a methoxymethyl group-containing urea compound and an acetoxymethyl group-containing phenol compound, and more preferred are a methoxymethyl group-containing melamine compound (e.g., hexamethoxymethylmelamine, etc.), a methoxymethyl group-containing glycoluril compound and a methoxymethyl group-containing urea compound. Methoxymethyl-containing melamine compounds are commercially available under trade names such as CYMEL300, CYMEL301, CYMEL303, and CYMEL305 (manufactured by Mitsui Cyanamid), methoxymethyl-containing glycoluril compounds are commercially available under trade names such as CYMEL1174 (manufactured by Mitsui Cyanamid), and methoxymethyl-containing urea compounds are commercially available under trade names such as MX290 (manufactured by Mitsui Cyanamid).

The content of the crosslinking agent (QN2) is usually 5 to 60 mol%, preferably 10 to 50 mol%, and more preferably 15 to 40 mol% with respect to the total acidic functional groups in the phenolic hydroxyl group-containing resin (QN1) from the viewpoint of reduction in the residual film ratio, meandering of the pattern, swelling, and developability.

Examples of the positive chemically amplified resin (QP) include resins having introduced into them protective groups (QP2) in which some or all of the hydrogen atoms of acidic functional groups in an alkali-soluble resin (QP1) containing one or more acidic functional groups such as a phenolic hydroxyl group, a carboxyl group, or a sulfonyl group are substituted with acid-dissociable groups.

The acid-dissociable group is a group that can be dissociated in the presence of a strong acid generated by the nonionic photoacid generator (a).

The protecting group-introduced resin (QP2) is itself alkali-insoluble or alkali-sparingly-soluble.

Examples of the alkali-soluble resin (QP1) include a phenolic hydroxyl group-containing resin (QP11), a carboxyl group-containing resin (QP12), and a sulfonic acid group-containing resin (QP 13).

As the phenolic hydroxyl group-containing resin (QP11), the same phenolic hydroxyl group-containing resin as that described above (QN1) can be used.

The carboxyl group-containing resin (QP12) is not particularly limited as long as it is a polymer having a carboxyl group, and can be obtained, for example, by vinyl-polymerizing a carboxyl group-containing vinyl monomer (Ba) and, if necessary, a hydrophobic group-containing vinyl monomer (Bb).

Examples of the carboxyl group-containing vinyl monomer (Ba) include unsaturated monocarboxylic acid [ (meth) acrylic acid, crotonic acid, cinnamic acid, etc. ], unsaturated polybasic (2-to 4-membered) carboxylic acid [ (anhydrous) maleic acid, itaconic acid, fumaric acid, citraconic acid, etc. ], alkyl (alkyl having 1 to 10 carbon atoms) ester of unsaturated polycarboxylic acid [ monoalkyl maleate, monoalkyl fumarate, monoalkyl citraconate, etc. ] and salts thereof [ alkali metal salts (sodium salts, potassium salts, etc.), alkaline earth metal salts (calcium salts, magnesium salts, etc.), amine salts, ammonium salts, etc. ].

Among these carboxyl group-containing vinyl monomers, unsaturated monocarboxylic acids are preferable, and (meth) acrylic acid is more preferable, from the viewpoint of polymerizability and availability.

Examples of the hydrophobic group-containing vinyl monomer (Bb) include (meth) acrylate (Bb1) and aromatic hydrocarbon monomer (Bb 2).

Examples of the (meth) acrylic acid ester (Bb1) include alkyl (meth) acrylates having an alkyl group of 1 to 20 carbon atoms [ e.g., methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc. ], and alicyclic group-containing (meth) acrylates [ (dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate, etc. ].

Examples of the aromatic hydrocarbon monomer (Bb2) include hydrocarbon monomers having a styrene skeleton [ e.g., styrene, α -methylstyrene, vinyltoluene, 2, 4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene, cyclohexylstyrene, and benzylstyrene ], and vinylnaphthalene.

The molar ratio of (Ba)/(Bb) charged monomer in the carboxyl group-containing resin (QP12) is usually 10 to 100/0 to 90, preferably 10 to 80/20 to 90, and more preferably 25 to 85/15 to 75, from the viewpoint of developability.

The sulfonic acid group-containing resin (QP13) is not particularly limited as long as it is a polymer having a sulfonic acid group, and can be obtained by, for example, vinyl polymerization of a sulfonic acid group-containing vinyl monomer (Bc) and, if necessary, a hydrophobic group-containing vinyl monomer (Bb).

As the hydrophobic group-containing vinyl monomer (Bb), the same hydrophobic group-containing vinyl monomer as described above can be used.

Examples of the sulfonic acid group-containing vinyl monomer (Bc) include vinylsulfonic acid, (meth) allylsulfonic acid, styrenesulfonic acid, α -methylstyrene sulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, and salts thereof. Examples of the salt include alkali metal (sodium, potassium, and the like) salts, alkaline earth metal (calcium, magnesium, and the like) salts, primary to tertiary amine salts, ammonium salts, quaternary ammonium salts, and the like.

The charging monomer molar ratio of (Bc)/(Bb) in the sulfonic acid group-containing resin (QP13) is usually 10 to 100/0 to 90, preferably 10 to 80/20 to 90, and more preferably 25 to 85/15 to 75, from the viewpoint of developability.

The HLB value of the alkali-soluble resin (QP1) is preferably within a range that differs depending on the resin skeleton of the alkali-soluble resin (QP1), more preferably 4 to 19, even more preferably 5 to 18, and particularly preferably 6 to 17.

When the HLB value is 4 or more, the developability during development is more excellent, and when it is 19 or less, the water resistance of the cured product is more excellent.

The HLB in the present invention is an HLB value by the microtia, and refers to a hydrophilicity-hydrophobicity balance value, and can be calculated from a ratio of an organic value and an inorganic value of an organic compound.

HLB ≈ 10 × inorganic/organic

The inorganic and organic values are described in detail on page 501 of "synthesis and application of surfactants" (published by the tradename of the Chao, Templemura) "; or "New surfactant Baohmen" (a lianwu press, manufactured by sanyo chemical industries, Ltd.) page 198.

Examples of the acid-dissociable group to be introduced into the resin (QP2) as a protecting group include a substituted methyl group, a 1-substituted ethyl group, a 1-branched alkyl group, a silyl group, a germyl group, an alkoxycarbonyl group, an acyl group, and a cyclic acid-dissociable group. These may be used alone or in combination of two or more.

Examples of the substituted methyl group include a methoxymethyl group, a methylthiomethyl group, an ethoxymethyl group, an ethylthiomethyl group, a methoxyethoxymethyl group, a benzyloxymethyl group, a benzylthiomethyl group, a phenacyl group, a bromobenzoylmethyl group, a methoxybenzoylmethyl group, a methylthiophenacyl group, an α -methylbenzoylmethyl group, a cyclopropylmethyl group, a benzyl group, a diphenylmethyl group, a triphenylmethyl group, a bromobenzyl group, a nitrobenzyl group, a methoxybenzyl group, a methylthiobenzyl group, an ethoxybenzyl group, an ethylthiobenzyl group, a piperonyl group, a methoxycarbonylmethyl group, an ethoxycarbonylmethyl group, an n-propoxycarbonylmethyl group, an isopropoxycarbonylmethyl group, an n-butoxycarbonylmethyl group, and a t-butoxycarbonylmethyl.

Examples of the 1-substituted ethyl group include a 1-methoxyethyl group, a 1-methylthioethyl group, a 1, 1-dimethoxyethyl group, a 1-ethoxyethyl group, a 1-ethylthioethyl group, a 1, 1-diethoxyethyl group, a 1-ethoxypropyl group, a 1-propoxyethyl group, a 1-cyclohexyloxyethyl group, a 1-phenoxyethyl group, a 1-phenylthioethyl group, a 1, 1-diphenoxyethyl group, a 1-benzyloxyethyl group, a 1-benzylthioethyl group, a 1-cyclopropylethyl group, a 1-phenylethyl group, a 1, 1-diphenylethyl group, a 1-methoxycarbonylethyl group, a 1-ethoxycarbonylethyl group, a 1-n-propoxycarbonylethyl group, a 1-isopropoxycarbonylethyl group, a 1-n-butoxycarbonylethyl group, and a 1-tert-butoxycarbonylethyl group.

Examples of the 1-branched alkyl group include an isopropyl group, a sec-butyl group, a tert-butyl group, a 1, 1-dimethylpropyl group, a 1-methylbutyl group, and a 1, 1-dimethylbutyl group.

Examples of the silyl group include trihydrocarbylsilyl groups such as trimethylsilyl group, ethyldimethylsilyl group, methyldiethylsilyl group, triethylsilyl group, isopropyldimethylsilyl group, methyldiisopropylsilyl group, triisopropylsilyl group, tert-butyldimethylsilyl group, methyl di-tert-butylsilyl group, tri-tert-butylsilyl group, phenyldimethylsilyl group, methyldiphenylsilyl group, and triphenylsilyl group.

Examples of germyl groups include: trihydrocarbylgermyl such as trimethylgermyl, ethyldimethylgermyl, methyldiethylgermyl, triethylgermyl, isopropyldimethylgermyl, methyldiisopropylgermyl, triisopropylgermyl, t-butyldimethylgermyl, methyl di-t-butylgermyl, tri-t-butylgermyl, phenyldimethylgermyl, methyldiphenylgermyl, triphenylgermyl and the like.

Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an isopropoxycarbonyl group, and a tert-butoxycarbonyl group.

Examples of the acyl group include an acetyl group, a propionyl group, a butyryl group, a heptanoyl group, a hexanoyl group, a pentanoyl group, a pivaloyl group, an isovaleryl group, a lauroyl group, a myristoyl group, a palmitoyl group, a stearoyl group, an oxalyl group, a malonyl group, a succinyl group, a glutaryl group, an adipoyl group, a pimeloyl group, an suberoyl group, a nonanedioyl group, a sebacoyl group, an acryloyl group, a propioyl group, a methacryloyl group, a crotonyl group, an oleoyl group, a maleoyl group, a fumaroyl group, a mesoconyl group, a campholoyl group, a benzoyl group, a phthaloyl group, an isophthaloyl group, a terephthaloyl group, a naphthoyl group, a toluoyl group, a atropoyl group, an atropoyl group, a cinnamoyl group, a furoyl group, a thenoyl group, a nicotinoyl group, an.

Examples of the cyclic acid-dissociable group include cyclopropyl, cyclopentyl, cyclohexyl, cyclohexenyl, 4-methoxycyclohexyl, tetrahydropyranyl, tetrahydrofuranyl, tetrahydrothiopyranyl, tetrahydrothienyl, 3-bromotetrahydropyranyl, 4-methoxytetrahydropyranyl, 4-methoxytetrahydrothiopyranyl, and 3-tetrahydrothiophene-1, 1-dioxide groups.

Among these acid-dissociable groups, preferred are tert-butyl, benzyl, 1-methoxyethyl, 1-ethoxyethyl, trimethylsilyl, tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tetrahydropyranyl, tetrahydrofuranyl, tetrahydrothiopyranyl, tetrahydrothienyl, and the like.

The introduction rate of the acid-dissociable group into the resin (QP2) (the ratio of the number of acid-dissociable groups to the total number of unprotected acidic functional groups and acid-dissociable groups in the resin (QP 2)) is not generally specified depending on the type of acid-dissociable group and the alkali-soluble resin into which the group is introduced, but is preferably 10 to 100%, and more preferably 15 to 100%.

The weight average molecular weight (hereinafter referred to as "Mw") of the protective group-introduced resin (QP2) in terms of polystyrene as measured by gel permeation chromatography is preferably 1000 to 150000, and more preferably 3000 to 100000.

The ratio (Mw/Mn) of Mw of the protecting group-introduced resin (QP2) to the polystyrene-equivalent number-average molecular weight (hereinafter referred to as "Mn") measured by gel permeation chromatography is usually 1 to 10, preferably 1 to 5.

The content of the nonionic photoacid generator (A) based on the weight of the solid content of the resin composition (Q) for lithography is preferably 0.001 to 20% by weight, more preferably 0.01 to 15% by weight, and particularly preferably 0.05 to 7% by weight.

When the content is 0.001% by weight or more, the sensitivity to ultraviolet rays can be more favorably exhibited, and when the content is 20% by weight or less, the physical properties of the insoluble portion can be more favorably exhibited with respect to the alkaline developer.

The resist using the resin composition (Q) for lithography of the present invention can be formed, for example, by: a resin solution obtained by dissolving (dissolving and dispersing in the case of including inorganic fine particles) in a predetermined organic solvent is applied onto a substrate by a known method such as spin coating, curtain coating, roll coating, spray coating, screen printing, and the solvent is dried by heating or hot air blowing.

The organic solvent for dissolving the resin composition (Q) for lithography of the present invention is not particularly limited as long as it can dissolve the resin composition and can adjust the resin solution to physical properties (viscosity and the like) applicable to spin coating and the like. For example, known solvents such as N-methylpyrrolidone, N-dimethylformamide, dimethyl sulfoxide, toluene, ethanol, cyclohexanone, methanol, methyl ethyl ketone, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate, acetone, and xylene can be used.

Among these solvents, solvents having a boiling point of 200 ℃ or lower (toluene, ethanol, cyclohexanone, methanol, methyl ethyl ketone, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate, acetone, and xylene) are preferable from the viewpoint of drying temperature and the like, and two or more kinds thereof may be used alone or in combination.

When an organic solvent is used, the amount of the solvent to be added is not particularly limited, and is usually preferably 30 to 1000% by weight, more preferably 40 to 900% by weight, and particularly preferably 50 to 800% by weight, based on the weight of the solid content of the resin composition (Q) for lithography.

The drying conditions of the resin solution after coating vary depending on the solvent used, and are preferably carried out at 50 to 200 ℃ for 2 to 30 minutes, and are appropriately determined by the amount (wt%) of the residual solvent of the resin composition for lithography (Q) after drying, and the like.

After the resist is formed on the substrate, light irradiation in a wiring pattern shape is performed. Then, after exposure and heating (PEB), alkali development is performed to form a wiring pattern.

As a method of irradiating light, a method of exposing a resist with active light via a photomask having a wiring pattern is given. The active optical fiber used for light irradiation is not particularly limited as long as it can decompose the nonionic photoacid generator (a) in the resin composition (Q) for lithography of the present invention.

Examples of the active light include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a metal halide lamp, an electron beam irradiation device, an X-ray irradiation device, and a laser (e.g., an argon laser, a dye laser, a nitrogen laser, an LED, and a helium-cadmium laser). Among these active rays, a high pressure mercury lamp and an ultrahigh pressure mercury lamp are preferable.

The temperature of the post-exposure heating (PEB) is usually 40 to 200 ℃, preferably 50 to 190 ℃, and more preferably 60 to 180 ℃. If the temperature is less than 40 ℃, the deprotection reaction and the crosslinking reaction cannot be sufficiently performed, and therefore, the difference in solubility between the ultraviolet-irradiated portion and the ultraviolet-unirradiated portion is insufficient, and the pattern cannot be formed, and if the temperature is higher than 200 ℃, there is a problem that the productivity is lowered.

The heating time is usually 0.5 to 120 minutes, preferably 1 to 90 minutes, and more preferably 2 to 90 minutes. If the time is less than 0.5 minute, it is difficult to control the time and temperature, and if it exceeds 120 minutes, there is a problem that the productivity is lowered.

As a method of the alkali development, a method of dissolving and removing the conductive pattern to a shape of the wiring pattern using an alkali developer is exemplified. The alkaline developer is not particularly limited as long as it is a condition that the solubility of the ultraviolet-irradiated portion and the ultraviolet-unirradiated portion of the resin composition (Q) for lithography can be different.

Examples of the alkaline developer include aqueous sodium hydroxide solution, aqueous potassium hydroxide solution, aqueous sodium bicarbonate solution, and aqueous tetramethylammonium salt solution.

These alkaline developers may also be added with a water-soluble organic solvent. Examples of the water-soluble organic solvent include methanol, ethanol, isopropanol, tetrahydrofuran, and N-methylpyrrolidone.

As the developing method, there are a dipping method, a shower method and a spray method using an alkaline developer, and the spray method is preferable.

The temperature of the developing solution is preferably 25 to 40 ℃. The developing time is appropriately determined according to the thickness of the resist.

Examples

The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples. Hereinafter,% represents% by weight and parts represent parts by weight unless otherwise specified.

Example 1

< Synthesis of nonionic photoacid Generator (A-1) >

8.3g (0.100mol) of N-methylhydroxyammonioate was dissolved in methanol (50mL), and 60g of a 10% methanol solution of potassium hydroxide was added dropwise while stirring at 0 ℃. Further, a solution prepared by dissolving 9.5g (0.050mol) of 2-naphthoyl chloride in THF (35mL) was added thereto, and the mixture was stirred for 1 hour. The reaction solution was returned to room temperature, stirred for 1 hour, and then distilled off by an evaporator. The residue was extracted with ethyl acetate and saturated brine, and the organic layer was separated, and then the solvent was distilled off with an evaporator to recover a white solid.

2.0g of the obtained solid and 3.8g (0.015mol) of (+) -10-camphorsulfonyl chloride were dissolved in chloroform (50mL), and 3.4g (0.015mol) of pyridine was added dropwise while stirring at 0 ℃. After stirring at 50 ℃ for 8 hours, the reaction solution was extracted with chloroform-water, and then the organic layer was removed under reduced pressure and the solvent was removed, whereby a brown oil was obtained. Then, the mixture was recrystallized from methanol to obtain 3.0g (0.007mol) of a sulfonic acid ester compound [ nonionic photoacid generator (A-1) ] represented by the above formula.

Example 2

< Synthesis of nonionic photoacid Generator (A-2) >

20.2g (0.100mol) of 5-methoxy-2-naphthoic acid was dissolved in thionyl chloride (100mL) and stirred at 80 ℃ for 2 hours. Then, thionyl chloride and hydrochloric acid generated in the system were distilled off under reduced pressure at 80 ℃ to obtain 20.0g (0.090mol) of 5-methoxy-2-naphthoyl chloride.

A sulfonic acid ester compound represented by the above formula [ nonionic photoacid generator (A-2) ] was obtained in the same manner as in example 1, except that 9.5g (0.050mol) of 2-naphthoyl chloride was changed to 11.0g (0.050mol) of 5-methoxy-2-naphthoyl chloride.

Example 3

< Synthesis of nonionic photoacid Generator (A-3) >

10.3g (0.100mol) of 3, 5-dihydroxynaphthoic acid was dissolved in acetone (120mL), and 83.6g (0.605mol) of potassium carbonate and 28.4g (0.221mol) of dimethylsulfuric acid were added to stir at 50 ℃ for 12 hours. The reaction solution was filtered to remove solids, and then the solvent was distilled off by an evaporator, followed by addition of water (50mL), methanol (50mL) and potassium hydroxide (10g) and stirring at 65 ℃ for 3 hours. Hydrochloric acid (100 g) was added to the solution, and the precipitated solid was recovered to obtain 3, 5-dimethoxy-2-naphthoic acid (20.0 g, 0.087 mol).

20.0g (0.087mol) of 3, 5-dimethoxy-2-naphthoic acid obtained herein was dissolved in thionyl chloride (100mL), and stirred at 80 ℃ for 2 hours. Then, thionyl chloride and hydrochloric acid generated in the system were distilled off under reduced pressure at 80 ℃ to obtain 20.0g (0.083mol) of 3, 5-dimethoxy-2-naphthoyl chloride.

A sulfonic acid ester compound represented by the above formula [ nonionic photoacid generator (A-3) ] was obtained in the same manner as in example 1, except that 9.5g (0.050mol) of 2-naphthoyl chloride was changed to 11.8g (0.050mol) of 3, 5-dimethoxy-2-naphthoyl chloride.

Example 4

< Synthesis of nonionic photoacid Generator (A-4) >

2.0g of the obtained white solid and 1.8g (0.015mol) of methanesulfonyl chloride were dissolved in chloroform (50mL), and 3.4g (0.015mol) of pyridine was added dropwise while stirring at 0 ℃. After stirring at 50 ℃ for 8 hours, the reaction solution was extracted with chloroform-water, and then the organic layer was removed under reduced pressure and the solvent was removed, whereby a brown oil was obtained. Then, the mixture was recrystallized from methanol to obtain a sulfonic acid ester compound [ nonionic photoacid generator (A-4) ] (0.007 mol).

Example 5

< Synthesis of nonionic photoacid Generator (A-5) >

2.0g of a white solid obtained by the same treatment as in example 4 and 4.1g (0.015mol) of pentafluorobenzenesulfonyl chloride were dissolved in chloroform (50mL), and 3.4g (0.015mol) of pyridine was added dropwise while stirring at 0 ℃. After stirring at 50 ℃ for 8 hours, the reaction solution was extracted with chloroform-water, and then the organic layer was removed under reduced pressure and the solvent was removed, whereby a brown oil was obtained. Then, the mixture was recrystallized from methanol to obtain a sulfonic acid ester compound [ nonionic photoacid generator (A-5) ] (0.007 mol).

Example 6

< Synthesis of nonionic photoacid Generator (A-6) >

Thiophenol 14.1g (0.128mol) and potassium hydroxide 7.2g (0.128mol) were dissolved in N, N-dimethylformamide (340mL), and the mixture was stirred at 70 ℃ for 1 hour. To this was added 32g (0.122mol) of methyl 4-iodobenzoate and 1.2g (0.006mol) of copper (I) iodide, and the mixture was stirred at 160 ℃ for 12 hours. After the reaction solution was returned to room temperature, hydrochloric acid was added to recover a precipitated solid, which was washed with 2-propanol to obtain 24g (0.104mol) of 4-phenylthiophenylbenzoic acid.

Acetyl chloride (9.8 g, 0.125mol) and aluminum chloride (33.3 g, 0.250mol) were dissolved in methylene chloride (200mL), and a solution of 4-phenylthiobenzoic acid (24 g, 0.104mol) in methylene chloride (36mL) was added dropwise while stirring at 0 ℃. After stirring at room temperature for 2 hours, the mixture was poured into ice water and further stirred for 1 hour. The precipitated solid was recovered and washed with an aqueous sodium hydroxide solution and methanol, whereby 24g (0.087mol) of 4-thio (4-acetylphenyl) benzoic acid was obtained.

24g (0.087mol) of 4-thio (4-acetylphenyl) benzoic acid obtained herein was dissolved in thionyl chloride (100mL) and stirred at 80 ℃ for 2 hours. Then, thionyl chloride and hydrochloric acid generated in the system were distilled off under reduced pressure at 80 ℃ to obtain 23g (0.083mol) of 4-thio (4-acetylphenyl) benzoyl chloride.

A sulfonate compound represented by the above formula [ nonionic photoacid generator (A-6) ] was obtained in the same manner as in example 1, except that 9.5g (0.050mol) of 2-naphthoyl chloride was changed to 14.3g (0.050mol) of 4-thio (4-acetylphenyl) benzoyl chloride.

Example 7

< Synthesis of nonionic photoacid Generator (A-7) >

19.0g (0.125mol) of 2-hydroxy-4-methoxybenzaldehyde was put into water, and 23.4g (0.162mol) of Meldrum's acid was added thereto with stirring. The mixture was stirred at 100 ℃ for 2 hours under reflux, and then returned to room temperature to recover a solid. This was washed with a mixed solvent of water and methanol, whereby 19.2g (0.087mol) of 7-methoxy-3-coumaric acid was obtained.

19.2g (0.087mol) of 7-methoxy-3-coumaric acid was dissolved in thionyl chloride (100mL) and stirred at 80 ℃ for 2 hours. Then, thionyl chloride and hydrochloric acid generated in the system were distilled off under reduced pressure at 80 ℃ to obtain 19.9g (0.083mol) of 7-methoxy-3-coumaroyl chloride.

A sulfonate compound represented by the above formula [ nonionic photoacid generator (A-7) ] was obtained in the same manner as in example 1, except that 9.5g (0.050mol) of 2-naphthoyl chloride was changed to 12.0g (0.050mol) of 7-methoxy-3-coumaroyl chloride.

Example 8

< Synthesis of nonionic photoacid Generator (A-8) >

19.5g (0.087mol) of 9-anthracenecarboxylic acid was dissolved in thionyl chloride (100mL) and stirred at 80 ℃ for 2 hours. Then, thionyl chloride and hydrochloric acid generated in the system were distilled off under reduced pressure at 80 ℃ to obtain 20.0g (0.083mol) of 9-anthracenecarbonyl chloride.

A sulfonic acid ester compound represented by the above formula [ nonionic photoacid generator (A-8) ] was obtained in the same manner as in example 1, except that 9.5g (0.050mol) of 2-naphthoyl chloride was changed to 12.0g (0.050mol) of 9-anthraceneyl chloride.

Comparative example 1

< Synthesis of nonionic photoacid Generator (A' -1) >

A mixture of naphthalic anhydride (3.0g, 0.050mmol), hydroxylamine hydrochloride 4.9g (0.070mol), and pyridine (50mL) was stirred at 100 ℃ for 10 hours. After cooling at room temperature, the reaction mixture was poured into 1N hydrochloric acid, and a precipitate was collected by filtration.

3.0g of the resulting precipitate was dissolved in pyridine (20mL), and 37.5g (0.150mmol) of (+) -10-camphorsulfonyl chloride was added dropwise while stirring at 0 ℃. After stirring at 25 ℃ for 8 hours, the reaction solution was extracted with dichloromethane-water, and then the organic layer was removed under reduced pressure and the solvent was removed, whereby an orange oil was obtained. Then, the resulting mixture was recrystallized from methanol to obtain a compound represented by the above formula [ nonionic photoacid generator (A' -1) ] (4.3g, 0.010 mmol).

Comparative example 2

< Synthesis of Ionic photoacid Generator (A' -2) >

While stirring 12.1 parts of diphenyl sulfoxide, 9.3 parts of diphenyl sulfide and 67.0 parts of (+) -10-camphorsulfonic acid, 7.9 parts of acetic anhydride was added dropwise thereto, and the mixture was reacted at 40 to 50 ℃ for 5 hours, then cooled to 25 ℃, and the reaction solution was poured into 121 parts of water and stirred at 50 ℃ for 8 hours to precipitate a yellow slightly viscous oily substance. The oily substance was extracted with ethyl acetate, the organic layer was washed with water several times, the solvent was distilled off from the organic layer, toluene was added to the obtained residue to dissolve it, hexane was then added thereto, and the mixture was stirred sufficiently at 10 ℃ for 1 hour and then allowed to stand. After 1 hour, the solution separated into two layers, and therefore, the upper layer was removed by liquid separation. Hexane was added to the remaining lower layer and upon thorough mixing at 25 ℃ pale yellow crystals precipitated. The reaction mixture was filtered, separated and dried under reduced pressure to obtain a compound represented by the above formula [ ionic photoacid generator (A' -2) ].

< evaluation of Properties >

The performance of the obtained nonionic photoacid generators (A-1) to (A-8) and the molar absorption coefficients of the nonionic photoacid generator (A '-1) and the ionic photoacid generator (A' -2), the curability of the resist, the thermal decomposition temperature, and the solubility in a solvent were evaluated by the following methods.

< molar absorptivity >

The synthesized photoacid generator was diluted to 0.25mmol/L with acetonitrile, and the absorbance of the sample was measured over a cell length of 1cm using an ultraviolet-visible spectrophotometer (UV-2550, manufactured by Shimadzu corporation) in a range of 200 to 500 nm. The molar absorptivity (. epsilon.) of i-ray (365nm) was calculated from the following formula₃₆₅)。

ε₃₆₅(L·mol^－1·cm^－1)＝A₃₆₅/(0.00025mol/L×1cm)

[ in the formula, A₃₆₅Represents an absorbance at 365nm]

< curability of resist >

Resin solutions of 75 parts of phenol resin (product of DIC corporation, "phenol TD 431"), 25 parts of melamine curing agent (product of Mitsui Cyanamid corporation, "CYMEL 300"), 1 part of synthesized photoacid generator, and 200 parts of propylene glycol monomethyl ether acetate (hereinafter, abbreviated as PGMEA) were applied onto glass substrates of 10cm each using a spin coater at 1000rpm for 10 seconds. Then, vacuum drying was performed at 25 ℃ for 5 minutes, and then drying was performed on a hot plate at 80 ℃ for 3 minutes, thereby forming a resist having a film thickness of about 3 μm. The resist was exposed to ultraviolet light having a wavelength defined by an L-34 (manufactured by Kenko corporation) filter by a predetermined amount over the entire surface thereof using an ultraviolet irradiation apparatus (HMW-661F-01, manufactured by ORC corporation). The cumulative exposure amount was measured at a wavelength of 365 nm. Subsequently, the substrate was exposed to light for 10 minutes by a downwind dryer at 120 ℃ and then heated (PEB), and then the substrate was immersed in a 0.5% potassium hydroxide solution for 30 seconds to develop the substrate, and then immediately washed with water and dried. The thickness of the resist film was measured using a shape measuring microscope (ultra-deep shape measuring microscope VK-8550, manufactured by KEYENCE K.K.). Here, the resist curability was evaluated based on the following criteria, based on the minimum exposure amount at which the film thickness of the resist before and after development was changed to 10% or less.

Very good: the minimum exposure amount is 200mJ/cm²The following

O: the lowest exposure is more than 200mJ/cm²And 300mJ/cm²The following

And (delta): the lowest exposure is more than 300mJ/cm²And 500mJ/cm²The following

X: the lowest exposure is more than 500mJ/cm²

< thermal decomposition temperature >

The change in weight of the synthesized photoacid generator from 30 ℃ to 500 ℃ was measured under a nitrogen atmosphere at a temperature rise of 10 ℃/min using a differential thermal/thermogravimetric simultaneous measurement apparatus (TG/DTA 6200, manufactured by SII), and the point of 2% weight reduction was defined as the thermal decomposition temperature.

< solubility in solvent >

0.1g of the synthesized photoacid generator was taken in a test tube, and 0.2g of organic solvents (butyl acetate, toluene, and PGMEA) was added at a time under temperature regulation at 25 ℃ until the photoacid generator was completely dissolved. When the solution was not completely dissolved even when 20g of the solution was added, the solution was evaluated as not dissolved.

The molar absorption coefficient, thermal decomposition temperature and solvent solubility of the nonionic photoacid generators (a-1) to (a-8) of the present invention prepared in examples, the comparative nonionic photoacid generator (a '-1) prepared in comparative example 1 and the comparative ionic photoacid generator (a' -2) prepared in comparative example 2 were measured by the methods described above. The results are shown in table 1.

[ Table 1]

As is clear from Table 1, the nonionic photoacid generators (A) of examples 1 to 8 of the present invention are excellent in resist curability and solubility in solvents, and have sufficient stability at thermal decomposition temperatures of 200 ℃ or higher.

On the other hand, it is found that the resist curability of comparative example 1 using a conventionally known nonionic photoacid generator and comparative example 2 using an ionic photoacid generator is insufficient, and the solubility in a solvent is also insufficient.

Industrial applicability

The sulfonate compound of the present invention is suitable as a photoacid generator used for positive resists, resist films, liquid resists, negative resists, resists for MEMS, photosensitive materials, nanoimprint materials, materials for microlithography, and the like. The resin composition (Q) for lithography according to the present invention is suitable for the above-mentioned uses.

Claims

1. A sulfonic acid ester compound characterized by being represented by the general formula (1),

in the formula (1), R1 represents 6-methoxynaphthyl, 3, 5-dimethoxynaphthyl, 7-methoxycoumarinyl or anthryl; r2 represents methyl; r3 represents a straight-chain alkyl group having 1 to 18 carbon atoms, a branched-chain alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms or an aryl group having 6 to 10 carbon atoms, and some or all of the hydrogen atoms may be substituted by fluorine.

2. A nonionic photoacid generator comprising the sulfonate ester compound according to claim 1.

3. A resin composition for lithography, comprising the nonionic photoacid generator according to claim 2.